1. Field of the Invention:
The present invention relates to a pull-out preventing mechanism for use with an attachment electronic unit housed within a housing of an electronic equipment which is arranged so that the attachment electronic unit can be attached to and detached from the housing. The present invention also relates to the electronic equipment having the pull-out preventing mechanism.
2. Description of the Related Art:
Recently, an information-oriented society has been rapidly developed and each member of society is deeply involved in the orientation in terms of its individual use of data terminal equipment or electronic equipment. When the electronic equipment such as a personal computer is utilized in a firm or the like, such electronic equipment tends to be operated in a day-and-night manner in order to provide service to its customer. Thus, if the electronic equipment comes to be uncontrollable due to any trouble or the like, a lot of inconvenience will be imposed on the customer. For this reason, the electronic equipment is requested to be more reliable. So, makers supplying the electronic equipment have responded to the request in such a manner that a main unit of the electronic equipment is arranged to have redundancy. That is, the electronic equipment is designed so that even if one of the attachment electronic units housed within the electronic equipment suffers from trouble, the electronic equipment is free from an uncontrollable state and hence always sustainable in day-and-night operation.
For example, if the electronic equipment is operated in a day-and-night manner as described above and one of the attached electronic unit provided in the electronic equipment suffers from trouble, the electronic equipment will be electrically influenced from noise or the like, with the result that the electronic equipment fails to function normally. In the worst case, the whole arrangement of the electronic equipment can be broken. Thus, when an operator deals with the electronic equipment, closest attention shall be paid. Accordingly, when the attached electronic unit provided in the electronic equipment suffers from trouble, it is necessary for the attachment electronic unit to be detached from the main body of the electronic equipment.
FIG. 1 is a diagram showing one example of a conventional electronic equipment. As shown in FIG. 1, electronic equipment 71 has an attachment electronic unit 51 housed therein. Housing 52 constituting electronic equipment 71 has attachment electronic unit 51, a main unit, not shown, or the like accommodated therein. Attachment electronic unit 51 is formed into a substantial box shape. On front face 51a of attachment electronic unit 51, there are provided handle 60 for detaching attachment electronic unit 51 from housing 52, switch 58 for turning on or off the attachment electronic unit, inlet 56 to which power supply plug 59 is inserted and electric power is supplied to the attachment electronic unit. On the rear face of attachment electronic unit 51, there is provided plug-in connector 51b through which signal transaction is effected with another unit.
On the other hand, housing 52 is formed to have an accommodating portion at which attachment electronic unit 51 is attached to or detached from. Opening 53 of the accommodating portion is formed on one face of housing 52. On an inner wall of housing 52, there is provided a connector corresponding to plug-in connector 51b which is disposed on one rear face of attachment electronic unit 51. When attachment electronic unit 51 is housed within housing 52, plug-in connector 51b is connected to a mating connector provided within housing 52.
When attachment electronic unit 52 is housed within housing 52, initially, the rear portion of attachment electronic unit 51 is inserted into opening 53 and then the whole body of attachment electronic unit 51 is inserted into housing 52 by using handle 60. Thus, substantially the whole body of attachment electronic unit 51 can be accommodated within housing 52. Housed attachment electronic unit 51 can be fixed in such a manner that plug-in connector 51b is matched with the mating connector provided within housing 52. Thereafter, attachment electronic unit 51 is fastened to housing 52 by using screws 61.
After attachment electronic unit 51 is fixed to housing 52, power supply plug 59 connected at one end of a cable is inserted into power receiving inlet 56. Then, power switch 58 is turned on so that attachment electronic unit 51 is energized. When attachment electronic unit 51 is to be replaced with another attachment electronic unit due to trouble with attachment electronic unit 51, power switch 58 is turned off and then power supply plug 59 is pulled out from power receiving inlet 56. Thereafter, screws 61 are removed from housing 52 and attachment electronic unit 51 is pulled out from housing 52.
However, the structure of the conventional electronic equipment shown in FIG. 1 encounters the following drawbacks. Initially, when attachment electronic unit 51 of electronic equipment 71 is to be replaced with another attachment electronic unit, an operator tends to leave power supply plug 59 connected to attachment electronic unit 51. When attachment electronic unit 51 is replaced with another unit, if power switch 58 is turned on and power supply plug 59 is left connected to power receiving inlet 56, attachment electronic unit 51 is pulled out from housing 52 under condition that attachment electronic unit 51 is energized. In this case, other units or the like within electronic equipment 71 can suffer from excessive current flow or noise can be generated. The excessive current or noise can influence circuits under operation, with the result that the energized circuits can fail to function normally. If the malfunction caused under the above condition is not serious, breakdown of electronic equipment 71 will be avoided. However, if the malfunction caused under the above condition is serious, electronic equipment 71 can break down.
An object of the present invention is to provide a pull-out preventing mechanism of an attachment electronic unit which can prohibit a user from unintentionally pulling out the attachment electronic unit from a housing when the attachment electronic unit housed within the housing to be detachable is replaced with another electronic unit under condition that the attachment electronic unit is connected with a power supply plug. Also, an object of the present invention is to provide an electronic equipment having such a pull-out preventing mechanism.
According to the present invention, if an electronic unit is housed within a housing of an electronic equipment so that the electronic unit can be attached to and detached from the housing, the electronic unit can be prevented from being pulled out from the housing under condition that the electronic unit is connected at its electric connecting part with a plug. More concretely, an engaging arm rotatably mounted on the electronic unit is engaged with an engaging portion provided on the housing, whereby the electronic unit can be prevented from being pulled out from the housing. With this arrangement, for example, if the electronic unit is connected at its electric connecting part with the plug and the electronic unit is energized through the plug, an operator can be prohibited from unintentionally pulling the electronic unit out from the housing of the electronic equipment. When the electronic unit is to be replaced with another electronic unit due to trouble caused in the electronic unit, the operator shall detach the plug from the electric connecting part of the electronic unit which is housed within the housing, and thereafter the operator pulls the attachment electronic unit out from the housing under the condition that the plug is removed from the electronic unit. According to the above arranged electronic equipment, the pull-out preventing mechanism for preventing the electronic unit from being pulled out from the housing will not be unlocked so long as the plug is detached from the electric connecting part of the electronic unit. Therefore, the electronic unit can be positively prevented from being pulled out from the housing under condition that the plug is connected to the electric connecting part of the electronic unit. With this arrangement, for example, if the operator unintentionally leaves the plug connected to the electronic unit, the operator can be prohibited from pulling the electronic unit out from the housing. In other words, when the operator intends to pull the electronic unit out from the housing, the operator is obliged to disconnect the plug from the electronic unit to completely cut the passage of power supply to the electronic unit. In this way, when the electronic unit is to be replaced with another electronic unit, the electronic equipment will be free from excessive current flow or noise generation at a portion other than the electronic unit. As a result, the circuits under operation can be free from influence coming from the excessive current flow or from noise. Accordingly, a malfunction can also be avoided in electronic unit under operation different from the electronic unit. Further, the electronic equipment having an attachment electronic unit which can be replaced with another electronic unit will not be deteriorated in its original performance. Therefore, the electronic equipment can be utilized with reliability.
The above and other objects, features and advantages of the present invention will become apparent from the following description with reference to the accompanying drawings which illustrate an example of the present invention.